System for folding napkins

ABSTRACT

A system for folding napkins feeds a continuous web over a folding board for producing a longitudinal fold in the web, the web is then severed transversely to form discrete segments which are transversely folded and creased by a first vacuum folding roll, the crease occurring transversely at a location intermediate the first transverse fold and the opposite edge of the segment. A second vacuum folding roll rotating adjacent the first then lifts the creased segment from the first folding roll at a location adjacent the crease to fold the segment along the crease line and thereby form an eight-ply napkin.

United States Patent Nystrand 51 Sept. 5, 1972 [54] SYSTEM FOR FOLDING NAPKINS [72] Ernst Daniel Nystrand, Green Bay,

Wis.

Assignee: Paper Converting Machine Company, lnc., Green Bay, Wis.

Filed: July 2, 1970 Appl. No.2 51,810

Inventor:

References Cited UNITED STATES PATENTS 7/1936 Schwartz ..270/69 9/1934 Christman ..270/69 1,566,079 12/ 1925 Christman et al. ..270/69 Primary Examiner-Robert W. Michell Assistant Examiner-L. R. Oremland AttorneyDawson, Tilton, Fallon & Lungmus ABSTRACT A system for folding napkins feeds a continuous web over a folding board for producing a longitudinal fold in the web, the web is then severed transversely to form discrete segments which are transversely folded and creased by a first vacuum folding roll, the crease occurring transversely at a location intermediate the first transverse fold and the opposite edge of the segment. A second vacuum folding roll rotating adjacent the first then lifts the creased segment from the first folding roll at a location adjacent the crease to fold the segment along the crease line and thereby form an eight-ply napkin.

9 Claims, 8 Drawing Figures Scott .270/ 64 Patented Sept. 5,1972 3,689,061

2 Sheets-Sheet 1 FIG. 2

ERNST DANIEL NYSTRAND ATT'YS Patented Sept 5, 1972 2 Sheets-Sheet 2 I,\VE;\{TOR: ERNST DANIEL NYSTRAND v BY: W, WW

SYSTEM FOR FOLDING NAPKINS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for folding napkins at high speed. Typically, the material used for napkins is a soft absorbent paper supplied in a continuous web. It is, of course, highly desirable to fold and cut the web into individual napkins at a very high speed in order to increase production.

2. Known Systems Systems are known for the high speed handling, folding, cutting and stacking of separate web segments such as napkins, hankies, etc. Some such devices are disclosed in the commonly owned U.S. Pats. Nos. 3,256,012, 3,254,889 and 3,247,746 which deal respectively with an orbital packing device, a stacking and handling apparatus, and a cut-off device.

A problem arises, however, in the high-speed manufacture of a napkin which has one longitudinal fold and two transverse folds so as to produce a final product having eight plies. It is difficult to form the second fold reliably without having to reduce the operating speed of the machine.

SUMMARY In the inventive system the web is fed from a source over a folding board to produce a continuous longitudinal fold in the web. The folded web is then fed onto a carrier roll where it is held by vacuum in partial wrapping engagement. A cutoff roll which carries aflyknife is mounted adjacent the carrier roll to sever the web into individual segments, the severed web being held against the carrier roll by means of the vacuum.

A second vacuum roll (sometimes referred to as the first folding roll) rotates in timed relation with the carrier roll and grasps the severed, longitudinally folded web segment at its transverse mid-point, to thereby produce a first transverse fold when the individual segment is removed from the carrier roll by the first folding roll. The segment is then carried by the primary folding roll into a nip between the primary folding roll and a crease roll to press the first transverse fold. The primary folding roll is also provided with a transverse crease bar or blade for forming a transverse crease in the napkin by pressing against a hard rubber pad on the crease roll. The folded, pressed and creased napkin is then carried by the primary folding roll to an auxiliary folding roll which is also provided with vacuum to pick up the napkin adjacent the mid-crease line for forming a second transverse fold. A second pressing roll then presses the second transverse crease against the auxiliary folding roll. The napkins are then removed from the second folding roll and stacked.

By forming the transverse mid-crease in the napkin after it has already been transversely folded once (and comprising four plies at this time), the present system has been able to reliably effect the second transverse fold without having to reduce the operating speed of Other features and advantages of the present invention will be apparent to persons skilled in the art from the following detailed description of a preferred embodiment wherein identical reference numerals will refer to like parts in the various views.

THE DRAWING DETAILED DESCRIPTION Turning then to FIG. 1, reference numeral 10 generally designates a paper web from which a folded napkin is formed. The web end is normally supplied from a supply roll (not shown) and fed over a folding board designated 11 (although hidden by the web 10) and having a V-shape to produce a longitudinal fold in the web 10. The web 10 is then fed between two nip rolls 12 for continuously pressing the longitudinal fold.

Although FIG. 1 illustrates apparatus for handling only a single web, persons skilled in the art will appreciate that usually the same machine will accommodate a number of such webs in side-by-side relation.

The longitudinally folded web 10 is fed into partial wrapping engagement with a carrier roll generally designated by reference numeral 13 which is mounted on a driven shaft 14 for rotation about a horizontal axis perpendicular to the plane of the page of FIG. 1. The carrier roll 13 is provided with first and second anvils, 15a and 15b at diagonally opposite positions so that two web segments may be formed per each revolution of the carrier roll 13. The driven shaft 14 is suitably joumaled in two side frame members forming the machine, the frame members being partially seen in FIG. 3 and designated respectively by reference numerals 17 and 18. It will also be noted from FIG. 3 that the machine as shown is adapted to process two separate webs.

Located adjacent the carrier roll 13 is a cut-off roll 19 which is mounted on a driven shaft 20 suitably journaled in the side frames 17, 18. The cutoff roll 19 is also provided with a pair of flyknives diagrammatically illustrated at 21 and 22 for engaging respectively the anvils 15a and 15b to sever the web 10 into individual segments. For additional details concerning the carrier roll 13 together with its anvils and the cut-off roll 19 and its associated flyknives, reference may be made to the above-described US Pat. No. 3,247,746. It will, however, be understood that the carrier roll 13 is provided with a number of radially extending conduits which communicate with a source of vacuum (not shown) for holding the severed web segments against the surface of the carrier roll 13. The carrier roll 13 in the illustrated embodiment rotates in a counterclockwise direction whereas the cutotf roll 19 rotates in a clockwise direction.

Located beneath and slightly to the side of the carrier roll 13 is a first or primary folding roll generally designated by reference numeral which is mounted on a driven shaft 26, again suitably journaled in the side frame members 17, 18. The primary folding roll 25 is also provided with a first plurality of radially extending conduits 28 and a second plurality of radially extending conduits 29. The conduits 28 communicate with an axial conduit 30, and the slots 29 communicate with a second axial conduit 31, the axial conduits 30 and 31 being selectively connected to and disconnected from a vacuum source in a manner presently to be described.

The primary folding roll 25 rotates in a clockwise direction in the illustrated embodiment, and located upstream (relative to this direction of travel) of each of the sets of vacuum conduits 28, 29 there are located creasing bars 32 and 33 respectively. Located to the right of the folding roll 25 is a creasing roll 35 which is mounted on a driven shaft 36 which is journaled in first and second side holding arms 38 and 39, only the arm 39 being shown in FIG. 1. The holding arms 38 and 39 are pivotally mounted on a transverse shaft 30 (see FIGS. 1 and 3) which is fastened to the side frame members 17 and 18. The arm 38 is provided with an aperture 42, and the arm 39 is provided with a similar aperture 43. A first bolt 44 extends through the aperture 42 and is threadably received in the side frame member 18. A second bolt 45 is received through the aperture 43 and is threadably received in the side frame member 17. Internally threaded apertures 46 and 47 are provided in the holding arm 39 communicating with the slot 43 for receiving opposing bolts to position the arm 39relative to the fixed bolt 45. By adjusting the two bolts (not shown) in the apertures 46 and 47, the holding arm 39 may be adjusted to position the creasing roll 35 relative to the primary folding roll 25 to achieve the desired amount of pressing in the first transverse fold of the napkin as well as to achieve the desired amount of creasing therein, as will presently be described. A similar opposing bolt arrangement is provided for the folding arm 38 relative to the fixed bolt 44 to position that arm, as persons skilled in the art will readily understand.

As already mentioned, there are shown in FIG. 3 two separate structures on each of the primary folding roll 25 and first creasing roll 35 for side-by-side creasing of napkins. Each station will, of course, be fed by a separate web. The creasing blades carried by the primary folding roll 25 are designated 33. Located in opposing relation relative to the creasing blades 33 on the crease roll 35 are hard rubber pads 50. Although there are two circumferentially spaced creasing blades 32, 33 on the primary folding roll 25, the circumference of that roll is twice the circumference of the pressing roll 35 so there is only one location along which the creasing pads 50 are provided on the crease roll 35.

Turning now to FIG. 2, there is shown a detailed drawing of the creasing blade 32 on the primary folding roll 25. It is secured in a recess 51 in the periphery of the primary folding roll 25 and held by a clamp 52 which is secured by means of a bolt (not shown) received in an internally threaded aperture 53 in the roll 25. The axis of the aperture 53 is inclined relative to a line extending radially of the roll 25 at an angle slightly less than 90. This permits convenient replacing of the creasing blade 32 which preferably may be made from spring steel having a thickness of about one-sixteenth inch and provided with a leading edge 32a which defines a transverse angle of The opposing hard rubber creasing pad 50 is similarly located in a recess 55 extending axially in the periphery of the roll 35 and provided with a clamping bar 56 secured by means of bolts threadedly received in apertures 57. Again, the apertures 57 are inclined relative to a line perpendicular to a radius of the roll 35 to permit replacement of the pad 50.

Turning again to FIG. 1, located beneath the primary folding roll 25 is a secondary folding roll generally designated by reference numeral 60 which is mounted on a driven shaft 61 and is provided with three sets of radially extending conduits 62, 63 and 64, all of which selectively are communicated with a source of vacuum. The shaft 61 is suitably journaled in the side frame members 17, 18, and located to the left side of the secondary or auxiliary folding roll 60 is a second pressing roll 66.

OPERATION Turning now to FIGS. 4A-4E, the operation of the present invention will be illustrated. The web 10, after being longitudinally folded by means of the folding board 11 and pressed by the nip rolls 12 is fed between the carrier roll 13 and cutoff roll 19 where individual segments (the one illustrated is designated by reference numeral 10a) are formed in partial wrapping engagement about the carrier roll 13. The individual segments are held against the periphery of the carrier roll 13 by means of the selective application of vacuum.

When the segment 10a reaches the position shown in FIG. 4A, a vacuum is generated in the radially extending slots of the primary folding roll 25 which grip the segment 10a along its transverse mid-section as at 10c. Each segment travelling in a first curved path about the carrier roll is thus lifted from that path by grasping its transverse mid-section and transferring the segment to a second path which diverges from the first path to form a complete fold. Thus, the transverse mid-section is led into the nip between the primary folding roll 25 and the first pressing (or crease) roll 35 as shown in FIG. 4B wherein the web 10a has a generally V-shaped transverse section. The pressing of the roll 35 against the primary folding roll 25 presses the leading transverse fold in the individual, severed segment 10a so that after passing between these rolls, the napkin is formed into four plies. As the transversely folded section 10a passes between the primary folding roll 25 and the crease roll 30, to about the position shown in FIG. 4C, one of the creasing blades on the primary folding roll 25 will engage the inner surface of the four-ply segment 10a to form a transverse crease at its newlyforrned mid-section designated by reference numeral 10d in FIG. 4C. The crease line is resiliently supported by the hard rubber pad on the crease roll. The transversely folded, creased segment 10a is still held by the vacuum generated in the primary folding roll 25, and the segment is transferred to the position shown in FIG. 4D wherein one of the sets of radially extending vacuum conduits of the secondary folding roll 60 couple with the four-ply segment 10a at a location upstream of the transverse crease 10d, at which time the vacuum is removed from the primary folding roll 25 and the trailing half section of the segment 10a is held against the periphery of the secondary folding roll 60 with the crease line d leading the segment (see FIG. 4B). The segment has now been transversely folded twice so as to form eight plies and the leading, creased edge will be pressed by the roll 66. After passing between the secondary folding roll 60 and the second pressing roll 66, the vacuum will be removed from the second pressing roll and the folded napkin will be taken from that roll and stacked in a conventional manner.

With the system disclosed above, wherein a longitudinally folded web is fed onto a vacuum-equipped carrier roll and cut into individual segments and then fed onto a vacuum-equipped primary folding roll for forming a first transverse fold, the present system is able to form, at high speed, a transverse crease in the four-ply napkin segment prior to forming the second fold in the thicker segment. We have found it desirable to feed the creased segment directly onto the second folding roll from the primary folding roll to minimize travel of the transversely folded segment.

Persons skilled in the art will be able to substitute different elements for certain of the elements that have been illustrated herein and to modify certain of the steps disclosed while continuing to practice the inventive principle; then it is therefore, intended that all such modifications and equivalents be covered as they are embraced within the spirit and scope of the appended claims.

I claim:

1. Apparatus for transverse folding comprising a frame; means on said frame for delivering a continuous web into a multiple folding path; first roll means in said path for transversely severing said web into segments; second roll means in said path including a first vacuum folding roll and a crease roll forming a nip with said first folding roll, said first folding roll coupling to the transverse midsection of each web segment and doubling each segment on itself while removing it from said first roll means and then feeding the double-over segment into said nip, one of said first folding roll and crease roll including a raised crease bar and the other including a hard rubber pad for backing the transverse mid-section of each segment whereby each doubledover segment is creased at its transverse mid-section when it passes through said nip formed by said folding roll and said crease roll; and third roll means in said path including a second vacuum folding roll coupling to each doubled-over segment on said first folding roll adjacent the crease formed in each segment for again doubling over each segment on itself about its transverse midsection.

2. The apparatus of claim 1 further comprising a fold board for continuously longitudinally folding said web and for delivering said folded web to said first-named means.

3. The apparatus of claim 1 wherein each of said folding roll and crease roll defines an axially extending recess for receiving said crease bar and said pad respectively and wherein each of said bar and pad are secured to its associated roll by means of bolt means extending inwardly of said rolls in threaded apertures inclined relative to radial lines of said rolls for facilitating replacement of said pad and crease bar.

4. The apparatus of claim 3 further comprising first and d ld membe rec ivi s 'd creas ol mear i f i' p isot ily moun tl ng the ends 0 holder means to said frame, and adjustment means intermediate the ends of each of said holder means for locating said crease roll relative to said folding roll to adjust the pressure of the nip defined by said folding roll and said crease roll and the pressure exerted by said crease bar against said pad.

5. A method of forming a folded napkin comprising: first forming a longitudinal fold in a web, then severing the web into individual segments and feeding it along a first curved path, then grasping each segment at its transverse mid-section and removing it from said first curved path into a second curved path diverging from the first curved path to form a first transverse fold, then pressing a crease bar against the transverse mid-section of each transversely folded segment while backing each segment with a yieldable pad and then grasping each creased segment adjacent the crease line and moving it to a third curved path divergent from the second curved path to form a second transverse fold in each segment.

6. The method of claim 5 wherein said first grasping step includes applying suction to each segment at its transverse mid-section by a rotating folding roll and wrapping the trailing half of each section about said folding roll, said crease bar being applied to the concave surface of each segment.

7. The method of claim 6 wherein said second grasping step includes applying suction to the convex surface of each segment on the first folding roll at a location immediately downstream of the crease line by a second rotating folding roll to wrap the trailing half of the transversely folded sections about said second folding roll.

8. A system for forming folded napkins from a continuous web comprising:

means for folding said web longitudinally, cutoff means including a rotating vacuum carrier roll for severing said web into individual segments and feeding them about said carrier roll, a first vacuum folding roll including a plurality of vacuum conduits for securing the transverse mid-section of each segment as the carrier roll transports each segment to a predetermined position and removing the segments from said carrier roll to form a first transverse fold, a crease bar on said first folding roll for underlying the transverse mid-section of a transversely folded napkin carried thereby, a crease roll adjacent said first folding roll for exerting pressure on said napkin against said crease bar to form a crease in said napkin, and a second vacuum folding roll including a plurality of vacuum conduits for securing each segment adjacent said crease line and removing it from said first folding roll to form a second transverse fold in each segment about the crease line formed therein.

9. The system of claim 8 wherein said crease roll also presses the first transverse fold in each segment, and further including holder means for adjusting the nip pressure and crease pressure exerted on each segment passing between said first folding roll and said crease roll. 

1. Apparatus for transverse folding comprising a frame; means on said frame for delivering a continuous web into a multiple folding path; first roll means in said path for transversely severing said web into segments; second roll means in said path including a first vacuum folding roll and a crease roll forming a nip with said first folding roll, said first folding roll coupling to the transverse midsection of each web segment and doubling each segment on itself while removing it from said first roll means and then feeding the double-over segment into said nip, one of said first folding roll and crease roll including a raised crease bar and the other including a hard rubber pad for backing the transverse mid-section of each segment whereby each doubled-over segment is creased at its transverse mid-section when it passes through said nip formed by said folding roll and said crease roll; and third roll means in said path including a second vacuum folding roll coupling to each doubled-over segment on said first folding roll adjacent the crease formed in each segment for again doubling over each segment on itself about its transverse midsection.
 2. The apparatus of claim 1 further comprising a fold board for continuously longitudinally folding said web and for delivering said folded web to said first-named means.
 3. The apparatus of claim 1 wherein each of said folding roll and crease roll defines an axially extending recess for receiving said crease bar and said pad respectively and wherein each of said bar and pad are secured to its associated roll by means of bolt means extending inwardly of said rolls in threaded apertures inclined relative to radial lines of said rolls for facilitating replacement of said pad and crease bar.
 4. The apparatus of claim 3 further comprising first and second holder members receiving said crease roll, means for pivotally mounting the distal ends of said holder means to said frame, and adjustment means intermediate the ends of each of said holder means for locating said crease roll relative to said folding roll to adjust the pressure of the nip defined by said folding roll and said crease roll and the pressure exerted by said crease bar against said pad.
 5. A method of forming a folded napkin comprising: first forming a longitudinal fold in a web, then severing the web into individual segments and feeding it along a first curved path, then grasping each segment at its transverse mid-section and removing it from said first curved path into a second curved path diverging from the first curved path to form a first transverse fold, then pressing a crease bar against the transverse mid-section of each transversely folded segment while backing each segment with a yieldable pad and then grasping each creased segment adjacent the crease line and moving it to a third curved path divergent from the second curved path to form a second transverse fold in each segment.
 6. The method of claim 5 wherein said first grasping step includes applying suction to each segment at its transverse mid-section by a rotating folding roll and wrapping the trailing half of each section about said folding roll, said crease bar being applied to the concave surface of each segment.
 7. The method of claim 6 wherein said second grasping step includes applying suction to the convex surface of each segment on the first folding roll at a location immediately downstream of the crease line by a second rotating folding roll to wrap the trailing half of the transversely folded sections about said second folding roll.
 8. A system for forming folded napkins from a continuous web comprising: means for folding said web longitudinally, cutoff means including a rotating vacuum carrier roll for severing said web into individual segments and feeding them about said carrier rOll, a first vacuum folding roll including a plurality of vacuum conduits for securing the transverse mid-section of each segment as the carrier roll transports each segment to a predetermined position and removing the segments from said carrier roll to form a first transverse fold, a crease bar on said first folding roll for underlying the transverse mid-section of a transversely folded napkin carried thereby, a crease roll adjacent said first folding roll for exerting pressure on said napkin against said crease bar to form a crease in said napkin, and a second vacuum folding roll including a plurality of vacuum conduits for securing each segment adjacent said crease line and removing it from said first folding roll to form a second transverse fold in each segment about the crease line formed therein.
 9. The system of claim 8 wherein said crease roll also presses the first transverse fold in each segment, and further including holder means for adjusting the nip pressure and crease pressure exerted on each segment passing between said first folding roll and said crease roll. 